Low birth weight and prematurity are important sources of neonatal mortality and morbidity worldwide. In developing countries, it is often difficult to measure birth weight and gestational duration directly, because most deliveries are not medically attended. Therefore, a number of studies have examined the utility of using neonatal anthropometric measurements as surrogate screening tests to identify low birth weight and preterm infants. The methodology employed in these studies, however, has not met the standards which have been recommended for the development of screening tests or medical decision rules. Our analysis will illustrate these standards using data from Ethiopia to develop an algorithm to enable practitioners in outpatient settings to use neonatal measurements to identify low birth weight, preterm infants needing referral for special care.